R E V IE W A R T IC L E
Review of methods for removing cast gold restorations R i c h a r d A . O liv a , D D S
t io n s w i l l h e lp th e d e n t is t d e c id e w h ic h r e m o v a l te c h n iq u e o r d e v ic e
T e c h n iq u e s a n d d e v ic e s fo r r e m o v a l o f cro w n s a re d escrib e d . C o m p a riso n s a re m a d e a cc o rd in g to w h ic h m e th o d is le a s t tra u m a tic to p a tie n ts a n d le a s t d e s tru c tiv e to to d a y ’s p re cisio n c a st crow ns.
s h o u ld be u se d .
Techniques and devices
J R l e m o v a l o f c r o w n s h a s lo n g b e e n a m a j o r c o n c e r n a n d p e r p le x in g
v ic e s d e s ig n e d f o r r e m o v a l o f c r o w n s
p r o b le m
to
s c r ib e d i n th e lit e r a t u r e a n d a ll d e
T e c h n iq u e s m o s t f r e q u e n tly d e scrib ed in th e literatu re a n d dev ices in v e n ted to rem ove cro w n s w ill be review ed.
d e n tis ts . M a n y te c h
r e q u ir e th e u s e o f fo rc e . A n y o n e o r a
n iq u e s h a v e b e e n d e s c rib e d in d e t a il
c o m b in a t io n o f fo rc e s c a n r e s u lt i n
in
i n j u r y to p a t ie n t, to o th , p u lp , a n d
( F ig 1 -3 ) a re u s e d p r i m a r ily f o r s l i t
p e r io d o n ta l tis s u e s .
th e lit e r a t u r e a n d d e v ic e s h a v e
b e e n in v e n t e d f o r th e s o le p u rp o s e o f
C R O W N S L IT T E R S . C r o w n s lit t e r s
r e m o v in g c r o w n s . D e n tis ts m a y h a v e
T h e te c h n iq u e o r d e v ic e f o r r e
t in g g o ld c r o w n s m a d e w i t h a c o n t o u r e d a x ia l b a n d a n d s w a g e d o c c lu
t o r e m o v e a c r o w n b e c a u s e : th e b in d
m o v a l o f a c r o w n s h o u ld b e s e le c te d
s a l s u rfa c e o f g o ld p la te . A x i a l c o n
in g c a s tin g is f i r m l y a f f ix e d a t th e
o n th e b a s is o f c lin ic a l e v a lu a tio n
t o u r a n d s w a g e d o c c lu s a l c r o w n s
t im e o f p r e c e m e n ta tio n f it t in g ; th e
a n d ju d g m e n t. T h e s e le c te d m e th o d
fa b r ic a te d f r o m a t h i n b a n d o f g o ld
c r o w n is in c o m p le t e ly se a te d a t th e
s h o u ld u se a p p lie d fo rc e t h a t is d i
p la te w e r e u s e d b e fo re g o ld c a s tin g
t im e o f c e m e n ta tio n ; th e c r o w n is
re c te d as c lo s e as p o s s ib le to th e lin e
te c h n iq u e s w e r e d e v e lo p e d , a n d a re
t e m p o r a r ily
o f d r a w o f th e c r o w n o r th e lo n g a x is
s im ila r to th e s w a g e d m e ta l te m p o
o f th e to o th .
ra ry
c e m e n te d ; p r o x im a l
c o n ta c ts a re lo s t b e c a u s e o f m o v e m e n t o f te e th ; m a r g in a l le a k a g e a n d
B e fo re th e
d e n tis t re m o v e s
a
c ro w n s
and
s t a in le s s
s te e l
c r o w n , th e s e q u e s tio n s s h o u ld b e
c r o w n s c u r r e n t ly a v a ila b le . T h e c r o w n w a s s l i t o n th e f a c ia l s u rfa c e
d o d o n t ic tr e a tm e n t is n e e d e d ; a h o le h a s w o r n t h r o u g h th e o c c lu s a l s u r
c o n s id e re d :
f r o m th e g in g iv a l m a r g in to th e o c
fa c e a n d r e p a ir is n e e d e d ; a n d p o r c e
m e n t th e c r o w n ?
d is s o lu t io n
la in
is
o f c e m e n t o c c u r; e n
c h ip p e d
o r fla k e d
on
a
— D id th e d e n tis t o r i g i n a l l y c e — W h a t ty p e o f c e m e n t w a s o r i g i n a lly u s e d ?
p o r c e la in - fu s e d - to - m e ta l c r o w n . T h e p r i m a r y c o n c e rn o f th e d e n tis t,
c e m e n te d ?
s h o u ld b e to p r e v e n t d a m a g e to to o t h
— Is th e
e n d o d o n tic a lly
tre a te d , c a u s in g th e t o o t h to b e m o re
tis s u e s a n d to m in im iz e tr a u m a to th e
s u s c e p tib le to c o r o n a l a n d r o o t f r a c
p a t ie n t . 1 T h e s e c o n d c o n c e rn s h o u ld b e to a v o id d a m a g e to th e c r o w n ; i t
tu re ?
c a n a lw a y s b e c o m p le te ly re m a d e .
u p , a d o w e l c o re , o r a n e n d o p o s t?
t h a t is
— Is th e re a r e in f o r c in g p in b u i l d — I f a p o s t is p re s e n t, is i t p a r t o f th e
c e m e n te d t e m p o r a r ily , p e r m a n e n tly ,
c r o w n c a s t in g
o r b in d in g a t th e t im e o f f i t t i n g re
d o w e l c o re a n d c o p in g ?
q u ir e s
f o r c e . A l l t e c h n iq u e s
8 4 0 ■ J A D A , V o l. 9 9 , N o v e m b e r 1 9 7 9
de
b o n d .2 W h e n th e c e m e n t b o n d w a s b ro k e n , o c c lu s a l p r y in g u s u a lly r e
to o th
s tr u c tu r e a n d p u lp a l o r p e r io d o n t a l
R e m o v a l o f a c ro w n
th e s lit a n d th e a x ia l b a n d w a s p r ie d f r o m th e to o th , b r e a k in g th e c e m e n t
— Is th e c r o w n g o in g t o b e r e
i n a t t e m p t in g to r e m o v e a c r o w n ,
c lu s a l m a r g in . A f t e r th e a x ia l b a n d w a s s lit , a n in s t r u m e n t w a s p la c e d in
o r is i t a s e p a ra te
A n s w e r s to th e s e a n d o th e r q u e s
m o v e d th e c r o w n .
C row n slitte rs are n o t effective if th e cro w n is m ad e of an axial b a n d of g old p la te, w ith a so ld ered axial co n to u r an d o cclu sal co n to u r, or e n tirely cast of gold. T h ick n ess an d h ard n e ss of gold o n th e axial su rface m ak e crow n slitte rs ineffective in th a t th e cro w n s c a n n o t be s lit by h a n d .1,2 C row n slitte rs m ay still be of som e
R E V IE W
A R T IC L E
u s e in s lit t in g a n d r e m o v in g s ta in le s s s te e l a n d t e m p o r a r y m e ta l c r o w n s . T h e r e a re th re e b a s ic ty p e s o f c r o w n s lit t e r s : p e r c u s s io n ( M o r r e ll’s C r o w n S lit t e r ) ; c o n s o lid a te d d e s ig n (C o n s o lid a t e d C r o w n S li t t e r ) ; a n d i m p r o v e d d e s ig n ( Im p r o v e d C r o w n S l i t te r). D R IL L IN G A H O L D , IN S E R T IN G A ROD, A N D P R Y IN G . W h e n a c r o w n is m a d e f r o m a n a x ia l b a n d w i t h a s o ld e re d g o ld a n d o c c lu s a l c o n t o u r o r w h e n a c r o w n is e n t ir e ly c a s t o f g o ld , r a th e r t h a n u s in g a c r o w n s lit t e r o r c u t t in g a
é""!1.11
US"_îHiii1-—■........ -
s lo t w i t h a fis s u r e b u r , t h is a lte r n a t iv e t e c h n iq u e ( F ig 4 ) w a s s u g g e s te d b y T y lm a n 2: “ a s m a ll h o le is d r i ll e d
Fig 1 ■ P ercussion cro w n slitter u ses cutting points in reverse m allet.
t h r o u g h th e b u c c a l s u rfa c e ju s t b e lo w th e p la n e o f th e o c c lu s a l s u rfa c e o f th e p r e p a r e d t o o th . T h is is c a r r ie d i n a lin g u a l d ir e c t io n b e tw e e n th e o c c lu s a l s u rfa c e o f th e c r o w n a n d a b o v e th e o c c lu s a l p la n e o f th e p r e p a r a tio n . T h is o p e n in g is m a d e o f a s u f f ic ie n t s iz e t o
p e r m i t th e i n s e r t i o n
of a
r o u n d , lo n g in s t r u m e n t w i t h w h ic h th e c r o w n is t h e n g e n tly r a is e d i n a n o c c lu s a l d ir e c t io n . ” Fig 2 ■ C onsolidated d esign crow n slitter.
M A L L E T A N D C H IS E L OR STEEL ROD. U s e o f a s tr a ig h t c h is e l o r s te e l r o d a n d a m a lle t ( F ig 5) to r e m o v e c r o w n s h a s b e e n s u g g e s te d .3,4 T h is t e c h n iq u e m u s t b e u s e d c a u t io u s ly b e c a u s e th e a n g u la r fo rc e c re a te d c a n b e d e s tr u c tiv e to te e th a n d p e r io d o n t a l tis s u e a n d c a n be tr a u m a t ic t o p a tie n ts . S P E C IA L L Y D E S IG N E D S C R E W S .
Fig 3 ■ Im proved crow n slitter.
J a c k s c re w s
a re
used
to
re m o v e
c r o w n s b y p r e d r i l l i n g a h o le i n th e o c c lu s a l s u rfa c e o f g o ld c r o w n s a n d
.V
b y in s e r t in g a s e lf - t h r e a d in g s c r e w in t o th e h o le u n t i l i t c o n ta c ts th e s u r fa c e o f th e to o th . A t t h a t p o in t , th e ja c k in g a c tio n b e g in s as th e s c r e w is t u r n e d f u r t h e r w i t h th e w r e n c h , a n d th e e n d o f th e s c r e w p r o tr u d e s b e n e a th th e s u rfa c e o f th e g o ld a n d f o r c e s a g a in s t t h e o c c lu s a l t o o t h s tr u c tu r e . A s th e s c r e w is t o r q u e d f u r t h e r t h r o u g h th e g o ld , th e c r o w n s h o u ld s a fe ly e le v a te o f f th e to o th . E ffe c tiv e u s e o f s p e c ia lly d e s ig n e d s c r e w s 1,2,5' 9 to r e m o v e c r o w n s d e p e n d s o n : a s u f f ic ie n t th ic k n e s s o f o c c lu s a l m e ta l to e n g a g e th e th re a d s o f th e s c re w ; s u f f ic ie n t th ic k n e s s o f s o lid t o o t h s tr u c tu r e o v e r th e p u lp c h a m b e r, th e a b s e n c e o f a p o s t- o r p in - r e in f o r c e d b u ild u p , a n d la c k o f a O liv a : R E M O V I N G C A S T G O L D R E S T O R A T IO N S ■ 8 4 1
R E V IE W
A R T IC L E
Fig 7 ■ Border d esign crow n rem over.
F ig 5 ■ M allet and chisel.
a n d a w r e n c h o r r o d ; a n d th e s c r e w t u r n e d b y a g e a re d s h a ft t h a t is o p e r
T h e L ynch d esig n (F ig 8) is sim ilar to th e B order d esig n an d differs o nly in th a t it has a p ressu re ro d rath e r th a n a seco n d screw to p ro d u ce th e elev atin g force. T h e seco n d screw is tu r n e d w ith a r o d r a th e r th a n a w re n ch an d exerts force ag a in st the p ressu re rod.
a te d b y t u r n in g a k n o b o u ts id e th e m o u t h . E w i n g 9 s u g g e s ts u s in g
a
s c r e w f r o m a tu b e o f D u c o c e m e n t; i t c a n be th re a d e d in t o a p r e d r ille d h o le
S3®»»
i n a c r o w n as a n a lte r n a tiv e to th e c o m m e r c ia lly a v a ila b le s c re w s .
SCREW T U R N E D B Y A GEARED S H A F T A N D OPERATED B Y T U R N IN G A K N O B O U T S ID E T H E M O U T H . A n e x a m p le o f t h is d e s ig n o f c r o w n r e m o v e r is th e
T H E SCREW A N D W R E N C H C R O W N REM O VE R . E x a m p le s o f s c r e w a n d w re n c h
c ro w n
re m o v e rs
a re : th e
c r o w n a n d b r id g e r e m o v e r, th e J. C. c r o w n a n d in la y r e m o v e r, a n d th e F ig 6 ■ T yp ical screw and w ren ch crow n re m over.
g u a r d ia n c r o w n re m o v e r. A l l th re e s c r e w a n d w r e n c h c r o w n re m o v e rs are s im ila r l y d e s ig n e d a n d u s e d .
p o s t c a s t as a p a r t o f th e c r o w n . W h e n s c re w s a re th re a d e d in t o a
SCREW IN A SCREW C O M B IN A T IO N CR O W N REM O VER. E x a m p le s o f th e
c r o w n w i t h a w r e n c h , m u c h to r q u in g
s c r e w i n s c r e w c o m b in a t io n c r o w n
fo rc e is c re a te d th a t c o u ld d a m a g e
r e m o v e rs a re th e B o r d e r d e s ig n f o r r e m o v in g r e s to r a tio n s 6 a n d th e d e
th e p e r io d o n t a l tis s u e s a n d fr a c tu r e th e c r o w n o f th e t o o th . I t is a ls o p o s
v ic e d e s ig n e d b y L y n c h f o r r e m o v in g
s ib le t o in s e r t th e ja c k s c r e w th r o u g h
r e s to r a tio n s fr o m te e th .7 T h e B o r d e r
th e o c c lu s a l t o o t h s tr u c tu r e o f th e
a n d L y n c h s c r e w c r o w n re m o v e rs a re
p r e p a r a tio n in t o th e p u lp c h a m b e r.
s im ila r l y d e s ig n e d .
K a r n o ff 8 sa ys, “ Ja ck s c re w s (s ic ) h a v e
T h e B o r d e r c r o w n r e m o v e r ( F ig 7)
p r o v e d d is a p p o in t in g i n m o s t cases;
h a s a s c r e w th a t is th re a d e d in t o a
w e r a r e ly f i n d e n o u g h th ic k n e s s o f
p r e d r ille d h o le in th e o c c lu s a l s u r
o c c lu s a l g o ld to e n g a g e th e s c r e w
fa c e o f th e c r o w n . A s e c o n d s c re w
th r e a d s .” T h r e e b a s ic d e s ig n s o f ja c k s c re w s
th re a d s in t o th e f ir s t a n d p r o v id e s th e e le v a tin g fo rc e . T h e s a m e p r i n c i p a l
h a v e b e e n d e s c rib e d : th e s c r e w a n d
o f c r o w n r e m o v a l as i n th e s c r e w a n d
w r e n c h ( F ig 6 ); th e s c r e w i n a s c r e w
w r e n c h c r o w n r e m o v e r is u s e d .
8 4 2 ■ J A D A , V o l. 9 9 , N o v e m b e r 1 9 7 9
Fig 8 ■ Lynch d esign crow n rem over.
R E V IE W
A R T IC L E
a n d to p r o v id e a m o r e fa v o r a b le a n g le o r fo rc e w h e n a p e r c u s s io n in s t r u m e n t is u s e d to r e m o v e a c r o w n . T h is t y p e o f d e v ic e ( F ig 1 0 ) is c la im e d to be a d v a n ta g e o u s as i t re d u c e s d a n g e r o f b re a k a g e , a v o id s g in g iv a l tis s u e s , a n d n e e d s n o h o le i n th e c r o w n f o r r e m o v a l. T h e ja w s a v a ila b le f o r re m o v in g c r o w n s i n c o n ju n c t io n w it h p e r c u s s io n in s t r u m e n t s a re o f th e s a m e b a s ic d e s ig n as th e C & R C r o w n A d a p t e r K i t a n d a re a v a ila b le w it h v a r io u s a d a p te rs . C L A W A N D SCREW C O M B IN A T IO N .
Fig 9 ■ J. Sarti Inlay and C rown R emover.
S a rti in la y e x t r a c t o r 1,5 ( F ig 9 ). T h e S a r ti ja c k s c r e w r e m o v e r o p e ra te s o n th e s a m e ja c k in g p r i n c i p l e as th e
C law s are d e s ig n e d to g rip a t th e m argins of a crow n. T h e screw does n o t th rea d in to th e cro w n b u t rath e r it goes th ro u g h a p re d rille d h o le on the o cclusal surface of th e crow n. A s the ratc h et on th e claw yoke is tu rn ed , the screw is forced a g a in st th e tooth s tru c tu re a n d cre ate s an elev atin g f o rc e . A n e x a m p le w o u ld be Rem ove-a-Crow n (F ig 11).
Fig 11 ■ R em ove-A -C row n.
a s t r a ig h t c h is e l a n d m a lle t. A re v e rs e m a lle t s h o u ld o n ly b e u s e d w h e n c r o w n s h a v e a lr e a d y b e e n p a r tia lly
lo o s e n e d b y o t h e r t e c h
n iq u e s . T h e r e v e rs e m a lle t s h o u ld n e v e r b e c o n s id e r e d
as t h e f i r s t
m e a n s o f c r o w n r e m o v a l. 1 T h e f o u r d e s ig n s o f r e v e r s e m a l le t s a re : a
o th e r ja c k s c r e w c r o w n re m o v e rs . D if fe re n c e s b e tw e e n th e S a r t i d e s ig n
R EVERSE M A L L E T . T h e r e a re f o u r
w e ig h t th a t s lid e s o v e r a s h a ft ( M o r
a n d o t h e r s a re t h a t t h e s c r e w
is
b a s ic d e s ig n s o f re v e rs e m a lle ts ; th e
r e l l ’ s c r o w n r e m o v e r ) ( F ig
t u r n e d b y r o t a t in g a k n u r le d k n o b a t
d e v ic e s h a v e t o b e u s e d c a u tio u s ly .
w e ig h t e d h a n d le th a t s lid e s o v e r a
th e e n d o f th e g e a re d s h a ft a n d th e
A s s o rte d
p o in t s a re a v a ila b le f o r
s h a ft3 ( F ig 1 3 ); a w e ig h t t h a t s lid e s
s c r e w h a s a b a ll u n iv e r s a lly m o u n te d
m o s t re v e rs e m a lle ts . T h e y a re d e
a lo n g a s h a ft th a t is s p r in g - p r o p e lle d
a t th e t ip .
s ig n e d to e n g a g e th e m a r g in o f th e
( G r e n fe ll, J .W ., p e rs o n a l c o m m u n ic a
c r o w n , e n g a g e th e
tio n )
in t e r p r o x im a l
( F ig
1 4 ); a n d
th e
1 2 ); a
e le c tr o
m a g n e tic re v e rs e m a lle t, p o w e r e d b y
C LAM PS A N D JAW S FO R USE W IT H
m a r g in , o r e n g a g e th e p o n t ic a re a o f
PERCUSSIO N IN S T R U M E N T S .1,2 T h e
f ix e d p a r t ia l d e n tu r e s . R e v e rs e m a l
e le c tr o m a g n e t ic e n e r g y 10 ( F ig
p r i n c ip a l o f d e s ig n o f th e s e d e v ic e s is
le ts c a n p ro d u c e d a n g e ro u s a n g u la r
E le c tr o m a g n e tic re v e rs e m a lle ts a re
to g ra s p th e o u te r s u rfa c e o f a c r o w n
fo rc e s lik e th o s e c re a te d b y th e u s e o f
n o t y e t a v a ila b le b u t t h e y re p r e s e n t
1 5 ).
a n in te r e s tin g c o n c e p t. F L U ID O R H Y D R A U L IC P R E S S U R E D E N T A L C R O W N E L E V A T O R .11 U s e o f t h is e le v a to r r e q u ir e s d r i l l i n g a h o le in th e o c c lu s a l s u rfa c e o f th e c r o w n , in t o w h ic h
a s p e c ia l c o n n e c t o r is
th re a d e d . T h e c o n n e c to r is a tta c h e d to a p u m p , a n d f l u i d p re s s u re f r o m th e p u m p is fo r c e d in t o th e in n e r s id e o f th e c r o w n th a t is b o n d e d to th e to o th . W h e n s u f f ic ie n t f l u i d p re s s u re is c re a te d o n th e in n e r s id e o f th e c r o w n , th e c e m e n t b o n d s e p a ra te s , a n d th e c r o w n
is r e m o v e d . F l u i d
p re s s u re d e n ta l c r o w n re m o v e rs ( F ig 1 6 ) a re n o t c u r r e n t ly a v a ila b le . SELECTED IN S T R U M E N T S FO R PR Y IN G . U s e o f p r y i n g in s tr u m e n t s is m a in ly
a p p l ic a b le
to b in d in g
or
f i r m l y a f fix e d c r o w n s a t th e t im e o f f i t t i n g a n d to t e m p o r a r ily c e m e n te d c ro w n s . A
la r g e s p o o n e le v a to r o r
s m a ll s u r g ic a l e le v a to r c a n b e u s e fu l Fig 10 ■ C & R C row n A dapter for u se w ith percu ssio n instrum ents.
f o r r e m o v in g “ s t u c k ” o r t e m p o r a r ily O liv a : R E M O V IN G C A S T G O L D R E S T O R A T IO N S ■ 843
R E V IE W
A R T IC L E
c e m e n te d c r o w n s w h e n p la c e d in th e i n t e r p r o x im a l m a r g in o r a t th e m a r g in a l r id g e a n d u s e d w i t h a p r y in g
r
fo rc e . H o r n 1 s u g g e s ts th e u s e o f a d u lle d h o e s c a le r (O rb a n ty p e ) — n o . 5 a n d n o . 6 s c a le rs a re e ffe c tiv e i n re m o v in g a c r y lic c r o w n s a n d f ix e d p a r t i a l d e n tu re s . In s tr u m e n ts f o r p r y i n g a re in e ff e c t iv e i n r e m o v in g p e rm a
F ig 12 ■ R everse m a llet w ith w eig h t that slid e s alon g shaft and accessory points.
n e n t ly c e m e n te d c r o w n s a n d , w h e n u s e d a t m a r g in s , c a n i r r e p a r a b ly d a m a g e th e t o o t h o r c r o w n . C R O W N R E M O V IN G FORCEPS. F o r c e p s a re u s e fu l f o r r e m o v in g c r o w n s t h a t a re t e m p o r a r ily c e m e n te d o r b in d in g a t th e t im e o f f it t in g . F o rc e p s
Fig 13 ■ W eighted-hand le reverse m allet— h a n d le slid e s alon g shaft.
a re n o t u s e fu l f o r r e m o v in g c r o w n s t h a t a re p e r m a n e n t ly c e m e n te d a l t h o u g h t h e y c a n b e u s e d to r e m o v e c ro w n s
th a t
w e re
p r e v io u s ly
lo o s e n e d b y o th e r m e a n s . F o r r e m o v a l o f p e r m a n e n t ly
c e m e n te d
c r o w n s , K a r n o f f 8 d e s c r ib e d u s e o f m o d if ie d fo rc e p s f o r r e m o v in g o r Fig 14 ■ Sp rin g-propelled w eig h t typ e cro w n rem over and seater.
t h o d o n t ic b a n d s . A l l th e d e s c rib e d fo rc e p s , e x c e p t th e m o d if ie d fo rc e p s used
f o r r e m o v in g
o r th o d o n tic
b a n d s , e n g a g e th e f a c ia l a n d lin g u a l a x ia l s u rfa c e s o f a c r o w n w i t h s e r r a te d b e a ks o r s h a rp p o in ts . H o w e p lie r s ( F ig 1 7 ), B a a d e p lie r s ( F ig 1 8 ) w i t h a d ju s ta b le s c re w s a n d s h a rp b e a k s ,4 a n d B a c k h a u s c la m p s ( F ig
1 9 ), w h i c h m u s t h a v e s h a r p
b e a k s to b e e ffe c tiv e (F is h e r, D ., p e r Fig 15 ■ E lectrom agnetic reverse m allet.
s o n a l c o m m u n ic a t io n ) , a re u s e d w i t h r o c k in g a n d t w is t in g fo rc e to r e m o v e c r o w n s . M o d if ie d p lie r s f o r r e m o v in g o r t h o d o n t ic b a n d s ( F ig 2 0 ), d e s c r ib e d b y K a r n o ff ,8 u se a s h a rp b e a k th a t e n g a g e s th e a x ia l s u rfa c e o f th e c r o w n a t th e g in g iv a l s u rfa c e a n d th e o th e r e n d o f th e p lie r s is in s e r te d in t o a p r e d r ille d h o le i n th e o c c lu s a l s u r fa c e o f th e c r o w n . B y c lo s in g th e p lie r s , fo rc e is a p p lie d a g a in s t th e o c c lu s a l to o t h s tr u c tu r e as th e s h a rp b e a k p rie s th e c r o w n in a n o c c lu s a l d ir e c t io n . K a r n o ff 8 s u g g e s ts t h a t a c r o w n w i t h a h o le in th e o c c lu s a l s u r fa c e is n o t h i n g t h o d o n t ic b a n d .
m o r e th a n a n o r
COPPER B A N D A N D CEM EN T O N RED CO M PO U N D . E w in g 9 s u g g e s ts u s e o f a c o p p e r b a n d f i l l e d w it h c e m e n t a n d a n a il t h r o u g h th e b a n d (F ig 2 1 ). A f t e r th e c e m e n t h a s h a rd e n e d , a r o c k in g a c t io n o n th e n a il w i l l lo o s e n th e c r o w n a n d p e r m it re m o v a l. Fig 16 ■ F luid p ressure dental crow n elevator.
8 4 4 ■ J A D A , V o l. 9 9 , N o v e m b e r 1 9 7 9
A s im ila r te c h n iq u e in v o lv e s u s e o f r e d c o m p o u n d in a c o p p e r b a n d a n d ,
R E V IE W
A R T IC L E S
Fig 17 ■ H ow e curved and straight p liers— serrated tips.
Fig 2 0 ■ M o d ified p lier s for rem ovin g or th odontic bands described by Karnoff.
Fig 18 ■ B aade pliers— adjustable screw and sharp beaks.4
Fig 21 ■ C opper band— cem en t an d n ail.
re v e rs e m a lle t f o r r e m o v in g c r o w n s a n d c o p in g s . C U T T IN G A S L O T W IT H A B U R A N D in s te a d o f a n a il, a lo o p e d le n g th o f b ra s s w ir e pa sse s th r o u g h th e c o p p e r
d e n tis t d e c id e s t h a t th e c r o w n is n o t
b a n d ( F ig 2 2 ). W h e n th e r e d c o m
t o b e r e p a ir e d a n d r e c e m e n te d o r th a t
p o u n d c o o ls , f o r c e f u l je r k in g o n th e
th e d e v ic e s a n d t e c h n iq u e s p r e v i
b ra s s w ir e o r u s e o f a p e rc u s s io n i n
o u s ly d e s c rib e d a re to o h a z a rd o u s ,
s tr u m e n t r e s u lts i n sa fe r e m o v a l o f
th e s a fe s t m e t h o d o f r e m o v a l is to c u t
th e c r o w n .
a s lo t a n d p r y th e c r o w n lo o s e w i t h
Fig 19 ■ B ack haus cla m p s m u st have sharp b eaks to be effective.
P R Y IN G W IT H IN S T R U M E N T S . I f th e
u s e o f a n in s t r u m e n t . 1‘3,9' 13 A s lo t is A C R Y L IC R E S IN CO PIN G . T h is te c h
c u t w i t h a h ig h - s p e e d c a r b id e b u r f o r
n iq u e w a s s u g g e s te d b y G a rv e r 12 a n d
m e ta l o r w it h
in v o lv e s th e u s e o f a c o p in g o f c o ld -
p o r c e la in . T h e s lo t is c u t in th e c r o w n
c u r in g a c r y lic r e s in th a t p r o v id e s a
ju s t t o th e d e p th o f th e c e m e n t, f r o m
m e c h a n ic a l p u rc h a s e ( F ig 2 3 ) f o r a
th e g in g iv a l m a r g in , u p th e fa c ia l s u r
a d ia m o n d b u r f o r
O liv a : R E M O V IN G C A S T G O L D R E S T O R A T IO N S
■ 845
R E V IE W
A R T IC L E
fa ce , a c ro s s th e o c c lu s a l s u rfa c e , a n d d o w n th e lin g u a l s u rfa c e w i t h i n 1.5 to 1 .0 m m
t io n ) . 9 T h e R i c h w i l c r o w n r e m o v e r is
o f th e lin g u a l g in g iv a l
p la c e d o n th e o c c lu s a l s u rfa c e o f th e
m a r g in . T h e u n c u t m e ta l a t th e l i n
c r o w n a n d th e p a tie n t is a s k e d to c lo s e in t o th e s u b s ta n c e ; t h is c o m
g u a l g in g iv a l m a r g in
k e e p s th e
h a lv e s o f th e c r o w n to g e th e r w h e n
p re s s e s i t b e t w e e n t h e
th e c e m e n t b o n d is b ro k e n . I f th e
t o o t h a n d c r o w n . R e m o v a l o f th e
o p p o s in g
c r o w n is c u t c o m p le te ly in h a lf, th e
c r o w n is a c c o m p lis h e d b y o p e n in g
f i r s t h a l f w i l l lo o s e n w i t h
p r y in g
th e m o u t h w i t h a r a p id a n d f o r c e f u l
fo rc e a n d i t w i l l c o m e o ff. T h is d o e s n o t le a v e a f u lc r u m to p r y a g a in s t to
m o t io n . A f t e r r e m o v a l, th e c r o w n w i l l b e t e m p o r a r ily a tta c h e d to th e
re m o v e th e o th e r h a lf o f th e c r o w n .
r e m o v e r a n d th e o p p o s in g to o th . T h e
A f t e r th e s lo t is c u t, a n a p p r o p r ia te
r e m o v e r a n d a tta c h e d c r o w n a re r e
in s t r u m e n t , s u c h as a la r g e s p o o n
m o v e d f r o m th e o p p o s in g to o th b y
e le v a t o r o r s u r g i c a l e le v a t o r , is
g r a s p in g t h e
p la c e d i n th e s lo t a n d p r y i n g fo rc e is
w i t h a s m a ll p ie c e o f g a u z e . R e m o v e r
a p p lie d
d i s t a l l y u n t i l th e c e m e n t
s u b s ta n c e is e a s ily w a s h e d f r o m th e
b o n d s e p a ra te s . T h e in s t r u m e n t is
s u rfa c e o f th e c r o w n w i t h so a p a n d
c ro w n a n d re m o v e r
th e n re v e rs e d a n d fo rc e is d ir e c te d
w a r m w a te r. A n y r e m a in in g p o r t io n
m e s ia lly ; th e lo o s e n e d h a lf o f th e
o f th e r e m o v e r s u b s ta n c e th a t is a t
c r o w n is u s e d as a f u lc r u m . W h e n th e c e m e n t b o n d o f th e m e s ia l h a lf o f th e
ta c h e d to th e o p p o s in g to o th c a n b e
Fig 22 ■ C opper band— red com pound and brass w ire loop.
c ro w n
s o lv e d w i t h
s e p a r a te s , g e n t l e f o r c e is
ta k e n o f f w i t h a n in s tr u m e n t o r d is w a rm
w a te r . C li n ic a l
a p p lie d i n a n o c c lu s a l d ir e c t io n a n d
ju d g m e n t h a s t o b e u s e d w h e n t r y in g
th e c r o w n is r e m o v e d .
to r e m o v e a c r o w n w i t h t h is te c h
R IC H W IL C R O W N A N D B R ID G E RE
r a r y a d h e s io n o f th e s u b s ta n c e . I f th e
M O VER . R ic h w il c ro w n re m o v e rs
o p p o s in g t o o t h o r its r e s to r a tio n is o f
( F ig 2 4 ), a c o m p le t e ly n e w c o n c e p t,
d o u b t f u l fir m n e s s , it , r a th e r t h a n th e
a re c o m p o s e d o f a s u b s ta n c e o f p l i
d e s ire d c r o w n , m a y b e re m o v e d .
n iq u e b e c a u s e o f th e s tr o n g te m p o
a b le r e s in w i t h
s t r o n g te m p o r a r y
a d h e s iv e p r o p e r tie s . R e m o v e rs are c o n v e n ie n tly
shaped
and
s iz e d .
T h e r e is n o n e e d f o r d r i l l i n g a h o le ,
D is c u s s io n A s c a n e a s ily b e o b s e rv e d f r o m th e
c la m p in g w i t h c la w s o r ja w s , p r y in g ,
in v e n te d
o r u s in g
p e r c u s s io n in s t r u m e n t s .
te c h n iq u e s , r e m o v a l o f c r o w n s is a
d e v ic e s
and
d e s c r ib e d
F o rc e f o r c r o w n r e m o v a l is g e n e ra te d b y th e p a tie n t. T h e s u b s ta n c e a d h e re s
c h a lle n g e th a t te s ts th e in t e llig e n c e ,
to th e s u rfa c e o f te e th a n d to g o ld ,
o f d e n tis ts . B e fo re 1 9 0 7 , r e m o v a l o f
p o r c e la in , a n d a c r y lic r e s in . U s e o f
c r o w n s w a s r e la t iv e ly s im p le . T h e
in g e n u ity , im a g in a tio n , a n d a b ili t y
R ic h w il c r o w n r e m o v e rs se e m s to b e
c o n to u r e d a x ia l b a n d w i t h s w a g e d
th e le a s t t r a u m a t ic a n d d e s tr u c tiv e
o c c lu s a l c r o w n s o f g o ld p la te w a s
m e th o d o f c r o w n re m o v a l y e t d e
e a s ily r e m o v e d w i t h
Fig 23 ■ A cry lic resin coping for m echanical
s c rib e d . I n i t i a l c lin ic a l te sts o f th e
c r o w n s litt e r . S in c e 1 9 0 7 , w h e n T a g
pu rchase.
re m o v e rs
s u c c e s s fu l
g a r t 14 in t r o d u c e d a m e th o d o f c a s tin g
( R a u t h , T . , p e r s o n a l c o m m u n ic a
g o ld , r e m o v a l o f c r o w n s h a s b e c o m e
a re p r o v i n g
Fig 24 ■ R ich w il crow n rem over. Left, rem over (A) placed on occlu sa l o f crow n (B) to be rem oved. Center, re m over (A) com pressed betw een cro w n (B) and natural tooth (C). R ight, rem over (A) attached to crow n (B) and nat ural tooth (C) w hen patient op en s m outh. 8 4 6 ■ J A D A , V o l. 9 9 , N o v e m b e r 1 9 7 9
th e u s e o f a
R E V IE W
p ro g ressiv ely m o re d ifficult as ca st in g te c h n iq u e s w ere perfected. Be c a u se p o rc e la in -fu s e d -to -m e ta l cro w n s h av e delicate p o rce lain sh ell o v er th in m e ta l c o p in g s, th e ir r e m o v al is ev en m ore com plicated. W hen, try in g to rem ove a crow n, th e d e n tist sh o u ld alw ays p roceed w ith c a u tio n . T h e le a s t p o s s ib le a m o u n t of force sh o u ld b e ap p lied . If th e d e n tist ever h as a d o u b t or rese r v atio n ab o u t th e success of th e p ro ced u re, h e sh o u ld stop before an u n n ecessary p ro b lem a n d trau m atic ex p erie n ce are created. R egardless of th e selected d evice or te ch n iq u e , the p a tie n t s h o u ld alw ays be info rm ed of th e p ro ce d u re an d possib le co m p li cations.
Summary M ost te c h n iq u e s a n d devices d e scrib ed for cro w n rem oval, in one w ay or ano th er, d estroy th e in teg rity o f to d a y ’s p r e c is io n c a st c ro w n s. T h ere w ere on ly th ree te c h n iq u e s d e
scrib ed th a t do n o t req u ire d rillin g a h ole, cu ttin g a n o tc h o r slot, c la m p in g w ith claw s or jaw s, p ry in g w ith in stru m e n ts, or g rasp in g w ith fo r cep s a n d p liers. T h ese are th e co p p e r b a n d fille d w ith ce m en t,9 th e co p in g of co ld -c u rin g acry lic re s in ,17 an d th e R ichw il cro w n rem over. T he safest a n d least trau m atic of all cro w n re m o v a l d e v ic e s a n d te c h n iq u e s is to cu t a slo t a n d p ry th e crow n loose. A lth o u g h th e cro w n is d e stro y e d , d am ag e to th e to o th is avoided.
The author thanks W illiam Bishop, University o f California at Los A n geles, S ch ool o f D en tistry, Dental Illustration Department, for th e il lustrations. Dr. O liva is assistant professor, section of fixed prosthodontics, School of Dentistry, U n i versity o f California at Los A n geles, 90024. A d dress requests for reprints to the author. 1. Horn, H.R. Practice con sid eration s for su ccessfu l crow n and bridge therapy. P h ilad el phia, W. B. Saunders Co., 1976. 2. T y lm a n , S.D . T h eory and p r a c tic e o f
A R T IC L E
crow n and bridge p rosth od on tics, ed 5. St. L ouis, C. V. M osby Co., 1965. 3. Roberts, D.H. Fixed bridge prosthesis. In stitute of Dental Surgery, Eastman D ental H os pital, Bristol, John W right & Son s, Ltd. 1973, p 225. 4. Kornfeld, M. M outh rehabilitation. C lini cal and laboratory procedures, ed 2. St. L ouis, C. V. M osby, 1974 p 584. 5. Sarti, J. Inlay extractor. U S Patent no. 2 ,6 4 0 ,2 6 6 J u n e 2 ,1 9 5 3 . 6. Border, S.L. R em oving tooth restorations. U S Patent no. 2,464,289, March 1949. 7. Lynch, H.F., and others. D evice for rem ov in g restoration s from teeth . U S P aten t no. 2,591,451, A pril 1952. 8. K am off, E.M. R em oving cem en ted crow ns and bridges w ith out destroying them . NYJ D en tal 4 5 (5 ):1 5 8 -1 5 9 ,1975. 9. E w in g , J.E. F ix e d p a r tia l p r o s th e s is . P h iladelph ia, Lea & Febiger, 1959, p 188. 10. Brodie, S.S., and others. A pparatus for the rem oval of cem en ted dental structures. US Patent no. 3,377,704, A pril 16, 1968. 11. Ballard, L.M. Dental crow n elevator. US Patent no. 3,653,127, A pril 4 ,1 9 7 2 . 12. Garver, D.S. A safe crow n-rem oval tech nique. ] Prosthet Dent 39(l):56-58, 1978. 13. W einberg, L.A. A tlas o f crow n and bridge prosthodontics. St. L ouis, C. V. M osby, 1965, p 226. 14. T aggart, W .H . A n e w an d a ccu rate m ethod of m aking gold inlays. Dent C osm os 49:1117-1121, 1907.
O li v a : R E M O V I N G C A S T G O L D R E S T O R A T IO N S ■ 8 4 7
Review of methods for removing cast gold restorations R i c h a r d A . O liv a , D D S
t io n s w i l l h e lp th e d e n t is t d e c id e w h ic h r e m o v a l te c h n iq u e o r d e v ic e
T e c h n iq u e s a n d d e v ic e s fo r r e m o v a l o f cro w n s a re d escrib e d . C o m p a riso n s a re m a d e a cc o rd in g to w h ic h m e th o d is le a s t tra u m a tic to p a tie n ts a n d le a s t d e s tru c tiv e to to d a y ’s p re cisio n c a st crow ns.
s h o u ld be u se d .
Techniques and devices
J R l e m o v a l o f c r o w n s h a s lo n g b e e n a m a j o r c o n c e r n a n d p e r p le x in g
v ic e s d e s ig n e d f o r r e m o v a l o f c r o w n s
p r o b le m
to
s c r ib e d i n th e lit e r a t u r e a n d a ll d e
T e c h n iq u e s m o s t f r e q u e n tly d e scrib ed in th e literatu re a n d dev ices in v e n ted to rem ove cro w n s w ill be review ed.
d e n tis ts . M a n y te c h
r e q u ir e th e u s e o f fo rc e . A n y o n e o r a
n iq u e s h a v e b e e n d e s c rib e d in d e t a il
c o m b in a t io n o f fo rc e s c a n r e s u lt i n
in
i n j u r y to p a t ie n t, to o th , p u lp , a n d
( F ig 1 -3 ) a re u s e d p r i m a r ily f o r s l i t
p e r io d o n ta l tis s u e s .
th e lit e r a t u r e a n d d e v ic e s h a v e
b e e n in v e n t e d f o r th e s o le p u rp o s e o f
C R O W N S L IT T E R S . C r o w n s lit t e r s
r e m o v in g c r o w n s . D e n tis ts m a y h a v e
T h e te c h n iq u e o r d e v ic e f o r r e
t in g g o ld c r o w n s m a d e w i t h a c o n t o u r e d a x ia l b a n d a n d s w a g e d o c c lu
t o r e m o v e a c r o w n b e c a u s e : th e b in d
m o v a l o f a c r o w n s h o u ld b e s e le c te d
s a l s u rfa c e o f g o ld p la te . A x i a l c o n
in g c a s tin g is f i r m l y a f f ix e d a t th e
o n th e b a s is o f c lin ic a l e v a lu a tio n
t o u r a n d s w a g e d o c c lu s a l c r o w n s
t im e o f p r e c e m e n ta tio n f it t in g ; th e
a n d ju d g m e n t. T h e s e le c te d m e th o d
fa b r ic a te d f r o m a t h i n b a n d o f g o ld
c r o w n is in c o m p le t e ly se a te d a t th e
s h o u ld u se a p p lie d fo rc e t h a t is d i
p la te w e r e u s e d b e fo re g o ld c a s tin g
t im e o f c e m e n ta tio n ; th e c r o w n is
re c te d as c lo s e as p o s s ib le to th e lin e
te c h n iq u e s w e r e d e v e lo p e d , a n d a re
t e m p o r a r ily
o f d r a w o f th e c r o w n o r th e lo n g a x is
s im ila r to th e s w a g e d m e ta l te m p o
o f th e to o th .
ra ry
c e m e n te d ; p r o x im a l
c o n ta c ts a re lo s t b e c a u s e o f m o v e m e n t o f te e th ; m a r g in a l le a k a g e a n d
B e fo re th e
d e n tis t re m o v e s
a
c ro w n s
and
s t a in le s s
s te e l
c r o w n , th e s e q u e s tio n s s h o u ld b e
c r o w n s c u r r e n t ly a v a ila b le . T h e c r o w n w a s s l i t o n th e f a c ia l s u rfa c e
d o d o n t ic tr e a tm e n t is n e e d e d ; a h o le h a s w o r n t h r o u g h th e o c c lu s a l s u r
c o n s id e re d :
f r o m th e g in g iv a l m a r g in to th e o c
fa c e a n d r e p a ir is n e e d e d ; a n d p o r c e
m e n t th e c r o w n ?
d is s o lu t io n
la in
is
o f c e m e n t o c c u r; e n
c h ip p e d
o r fla k e d
on
a
— D id th e d e n tis t o r i g i n a l l y c e — W h a t ty p e o f c e m e n t w a s o r i g i n a lly u s e d ?
p o r c e la in - fu s e d - to - m e ta l c r o w n . T h e p r i m a r y c o n c e rn o f th e d e n tis t,
c e m e n te d ?
s h o u ld b e to p r e v e n t d a m a g e to to o t h
— Is th e
e n d o d o n tic a lly
tre a te d , c a u s in g th e t o o t h to b e m o re
tis s u e s a n d to m in im iz e tr a u m a to th e
s u s c e p tib le to c o r o n a l a n d r o o t f r a c
p a t ie n t . 1 T h e s e c o n d c o n c e rn s h o u ld b e to a v o id d a m a g e to th e c r o w n ; i t
tu re ?
c a n a lw a y s b e c o m p le te ly re m a d e .
u p , a d o w e l c o re , o r a n e n d o p o s t?
t h a t is
— Is th e re a r e in f o r c in g p in b u i l d — I f a p o s t is p re s e n t, is i t p a r t o f th e
c e m e n te d t e m p o r a r ily , p e r m a n e n tly ,
c r o w n c a s t in g
o r b in d in g a t th e t im e o f f i t t i n g re
d o w e l c o re a n d c o p in g ?
q u ir e s
f o r c e . A l l t e c h n iq u e s
8 4 0 ■ J A D A , V o l. 9 9 , N o v e m b e r 1 9 7 9
de
b o n d .2 W h e n th e c e m e n t b o n d w a s b ro k e n , o c c lu s a l p r y in g u s u a lly r e
to o th
s tr u c tu r e a n d p u lp a l o r p e r io d o n t a l
R e m o v a l o f a c ro w n
th e s lit a n d th e a x ia l b a n d w a s p r ie d f r o m th e to o th , b r e a k in g th e c e m e n t
— Is th e c r o w n g o in g t o b e r e
i n a t t e m p t in g to r e m o v e a c r o w n ,
c lu s a l m a r g in . A f t e r th e a x ia l b a n d w a s s lit , a n in s t r u m e n t w a s p la c e d in
o r is i t a s e p a ra te
A n s w e r s to th e s e a n d o th e r q u e s
m o v e d th e c r o w n .
C row n slitte rs are n o t effective if th e cro w n is m ad e of an axial b a n d of g old p la te, w ith a so ld ered axial co n to u r an d o cclu sal co n to u r, or e n tirely cast of gold. T h ick n ess an d h ard n e ss of gold o n th e axial su rface m ak e crow n slitte rs ineffective in th a t th e cro w n s c a n n o t be s lit by h a n d .1,2 C row n slitte rs m ay still be of som e
R E V IE W
A R T IC L E
u s e in s lit t in g a n d r e m o v in g s ta in le s s s te e l a n d t e m p o r a r y m e ta l c r o w n s . T h e r e a re th re e b a s ic ty p e s o f c r o w n s lit t e r s : p e r c u s s io n ( M o r r e ll’s C r o w n S lit t e r ) ; c o n s o lid a te d d e s ig n (C o n s o lid a t e d C r o w n S li t t e r ) ; a n d i m p r o v e d d e s ig n ( Im p r o v e d C r o w n S l i t te r). D R IL L IN G A H O L D , IN S E R T IN G A ROD, A N D P R Y IN G . W h e n a c r o w n is m a d e f r o m a n a x ia l b a n d w i t h a s o ld e re d g o ld a n d o c c lu s a l c o n t o u r o r w h e n a c r o w n is e n t ir e ly c a s t o f g o ld , r a th e r t h a n u s in g a c r o w n s lit t e r o r c u t t in g a
é""!1.11
US"_îHiii1-—■........ -
s lo t w i t h a fis s u r e b u r , t h is a lte r n a t iv e t e c h n iq u e ( F ig 4 ) w a s s u g g e s te d b y T y lm a n 2: “ a s m a ll h o le is d r i ll e d
Fig 1 ■ P ercussion cro w n slitter u ses cutting points in reverse m allet.
t h r o u g h th e b u c c a l s u rfa c e ju s t b e lo w th e p la n e o f th e o c c lu s a l s u rfa c e o f th e p r e p a r e d t o o th . T h is is c a r r ie d i n a lin g u a l d ir e c t io n b e tw e e n th e o c c lu s a l s u rfa c e o f th e c r o w n a n d a b o v e th e o c c lu s a l p la n e o f th e p r e p a r a tio n . T h is o p e n in g is m a d e o f a s u f f ic ie n t s iz e t o
p e r m i t th e i n s e r t i o n
of a
r o u n d , lo n g in s t r u m e n t w i t h w h ic h th e c r o w n is t h e n g e n tly r a is e d i n a n o c c lu s a l d ir e c t io n . ” Fig 2 ■ C onsolidated d esign crow n slitter.
M A L L E T A N D C H IS E L OR STEEL ROD. U s e o f a s tr a ig h t c h is e l o r s te e l r o d a n d a m a lle t ( F ig 5) to r e m o v e c r o w n s h a s b e e n s u g g e s te d .3,4 T h is t e c h n iq u e m u s t b e u s e d c a u t io u s ly b e c a u s e th e a n g u la r fo rc e c re a te d c a n b e d e s tr u c tiv e to te e th a n d p e r io d o n t a l tis s u e a n d c a n be tr a u m a t ic t o p a tie n ts . S P E C IA L L Y D E S IG N E D S C R E W S .
Fig 3 ■ Im proved crow n slitter.
J a c k s c re w s
a re
used
to
re m o v e
c r o w n s b y p r e d r i l l i n g a h o le i n th e o c c lu s a l s u rfa c e o f g o ld c r o w n s a n d
.V
b y in s e r t in g a s e lf - t h r e a d in g s c r e w in t o th e h o le u n t i l i t c o n ta c ts th e s u r fa c e o f th e to o th . A t t h a t p o in t , th e ja c k in g a c tio n b e g in s as th e s c r e w is t u r n e d f u r t h e r w i t h th e w r e n c h , a n d th e e n d o f th e s c r e w p r o tr u d e s b e n e a th th e s u rfa c e o f th e g o ld a n d f o r c e s a g a in s t t h e o c c lu s a l t o o t h s tr u c tu r e . A s th e s c r e w is t o r q u e d f u r t h e r t h r o u g h th e g o ld , th e c r o w n s h o u ld s a fe ly e le v a te o f f th e to o th . E ffe c tiv e u s e o f s p e c ia lly d e s ig n e d s c r e w s 1,2,5' 9 to r e m o v e c r o w n s d e p e n d s o n : a s u f f ic ie n t th ic k n e s s o f o c c lu s a l m e ta l to e n g a g e th e th re a d s o f th e s c re w ; s u f f ic ie n t th ic k n e s s o f s o lid t o o t h s tr u c tu r e o v e r th e p u lp c h a m b e r, th e a b s e n c e o f a p o s t- o r p in - r e in f o r c e d b u ild u p , a n d la c k o f a O liv a : R E M O V I N G C A S T G O L D R E S T O R A T IO N S ■ 8 4 1
R E V IE W
A R T IC L E
Fig 7 ■ Border d esign crow n rem over.
F ig 5 ■ M allet and chisel.
a n d a w r e n c h o r r o d ; a n d th e s c r e w t u r n e d b y a g e a re d s h a ft t h a t is o p e r
T h e L ynch d esig n (F ig 8) is sim ilar to th e B order d esig n an d differs o nly in th a t it has a p ressu re ro d rath e r th a n a seco n d screw to p ro d u ce th e elev atin g force. T h e seco n d screw is tu r n e d w ith a r o d r a th e r th a n a w re n ch an d exerts force ag a in st the p ressu re rod.
a te d b y t u r n in g a k n o b o u ts id e th e m o u t h . E w i n g 9 s u g g e s ts u s in g
a
s c r e w f r o m a tu b e o f D u c o c e m e n t; i t c a n be th re a d e d in t o a p r e d r ille d h o le
S3®»»
i n a c r o w n as a n a lte r n a tiv e to th e c o m m e r c ia lly a v a ila b le s c re w s .
SCREW T U R N E D B Y A GEARED S H A F T A N D OPERATED B Y T U R N IN G A K N O B O U T S ID E T H E M O U T H . A n e x a m p le o f t h is d e s ig n o f c r o w n r e m o v e r is th e
T H E SCREW A N D W R E N C H C R O W N REM O VE R . E x a m p le s o f s c r e w a n d w re n c h
c ro w n
re m o v e rs
a re : th e
c r o w n a n d b r id g e r e m o v e r, th e J. C. c r o w n a n d in la y r e m o v e r, a n d th e F ig 6 ■ T yp ical screw and w ren ch crow n re m over.
g u a r d ia n c r o w n re m o v e r. A l l th re e s c r e w a n d w r e n c h c r o w n re m o v e rs are s im ila r l y d e s ig n e d a n d u s e d .
p o s t c a s t as a p a r t o f th e c r o w n . W h e n s c re w s a re th re a d e d in t o a
SCREW IN A SCREW C O M B IN A T IO N CR O W N REM O VER. E x a m p le s o f th e
c r o w n w i t h a w r e n c h , m u c h to r q u in g
s c r e w i n s c r e w c o m b in a t io n c r o w n
fo rc e is c re a te d th a t c o u ld d a m a g e
r e m o v e rs a re th e B o r d e r d e s ig n f o r r e m o v in g r e s to r a tio n s 6 a n d th e d e
th e p e r io d o n t a l tis s u e s a n d fr a c tu r e th e c r o w n o f th e t o o th . I t is a ls o p o s
v ic e d e s ig n e d b y L y n c h f o r r e m o v in g
s ib le t o in s e r t th e ja c k s c r e w th r o u g h
r e s to r a tio n s fr o m te e th .7 T h e B o r d e r
th e o c c lu s a l t o o t h s tr u c tu r e o f th e
a n d L y n c h s c r e w c r o w n re m o v e rs a re
p r e p a r a tio n in t o th e p u lp c h a m b e r.
s im ila r l y d e s ig n e d .
K a r n o ff 8 sa ys, “ Ja ck s c re w s (s ic ) h a v e
T h e B o r d e r c r o w n r e m o v e r ( F ig 7)
p r o v e d d is a p p o in t in g i n m o s t cases;
h a s a s c r e w th a t is th re a d e d in t o a
w e r a r e ly f i n d e n o u g h th ic k n e s s o f
p r e d r ille d h o le in th e o c c lu s a l s u r
o c c lu s a l g o ld to e n g a g e th e s c r e w
fa c e o f th e c r o w n . A s e c o n d s c re w
th r e a d s .” T h r e e b a s ic d e s ig n s o f ja c k s c re w s
th re a d s in t o th e f ir s t a n d p r o v id e s th e e le v a tin g fo rc e . T h e s a m e p r i n c i p a l
h a v e b e e n d e s c rib e d : th e s c r e w a n d
o f c r o w n r e m o v a l as i n th e s c r e w a n d
w r e n c h ( F ig 6 ); th e s c r e w i n a s c r e w
w r e n c h c r o w n r e m o v e r is u s e d .
8 4 2 ■ J A D A , V o l. 9 9 , N o v e m b e r 1 9 7 9
Fig 8 ■ Lynch d esign crow n rem over.
R E V IE W
A R T IC L E
a n d to p r o v id e a m o r e fa v o r a b le a n g le o r fo rc e w h e n a p e r c u s s io n in s t r u m e n t is u s e d to r e m o v e a c r o w n . T h is t y p e o f d e v ic e ( F ig 1 0 ) is c la im e d to be a d v a n ta g e o u s as i t re d u c e s d a n g e r o f b re a k a g e , a v o id s g in g iv a l tis s u e s , a n d n e e d s n o h o le i n th e c r o w n f o r r e m o v a l. T h e ja w s a v a ila b le f o r re m o v in g c r o w n s i n c o n ju n c t io n w it h p e r c u s s io n in s t r u m e n t s a re o f th e s a m e b a s ic d e s ig n as th e C & R C r o w n A d a p t e r K i t a n d a re a v a ila b le w it h v a r io u s a d a p te rs . C L A W A N D SCREW C O M B IN A T IO N .
Fig 9 ■ J. Sarti Inlay and C rown R emover.
S a rti in la y e x t r a c t o r 1,5 ( F ig 9 ). T h e S a r ti ja c k s c r e w r e m o v e r o p e ra te s o n th e s a m e ja c k in g p r i n c i p l e as th e
C law s are d e s ig n e d to g rip a t th e m argins of a crow n. T h e screw does n o t th rea d in to th e cro w n b u t rath e r it goes th ro u g h a p re d rille d h o le on the o cclusal surface of th e crow n. A s the ratc h et on th e claw yoke is tu rn ed , the screw is forced a g a in st th e tooth s tru c tu re a n d cre ate s an elev atin g f o rc e . A n e x a m p le w o u ld be Rem ove-a-Crow n (F ig 11).
Fig 11 ■ R em ove-A -C row n.
a s t r a ig h t c h is e l a n d m a lle t. A re v e rs e m a lle t s h o u ld o n ly b e u s e d w h e n c r o w n s h a v e a lr e a d y b e e n p a r tia lly
lo o s e n e d b y o t h e r t e c h
n iq u e s . T h e r e v e rs e m a lle t s h o u ld n e v e r b e c o n s id e r e d
as t h e f i r s t
m e a n s o f c r o w n r e m o v a l. 1 T h e f o u r d e s ig n s o f r e v e r s e m a l le t s a re : a
o th e r ja c k s c r e w c r o w n re m o v e rs . D if fe re n c e s b e tw e e n th e S a r t i d e s ig n
R EVERSE M A L L E T . T h e r e a re f o u r
w e ig h t th a t s lid e s o v e r a s h a ft ( M o r
a n d o t h e r s a re t h a t t h e s c r e w
is
b a s ic d e s ig n s o f re v e rs e m a lle ts ; th e
r e l l ’ s c r o w n r e m o v e r ) ( F ig
t u r n e d b y r o t a t in g a k n u r le d k n o b a t
d e v ic e s h a v e t o b e u s e d c a u tio u s ly .
w e ig h t e d h a n d le th a t s lid e s o v e r a
th e e n d o f th e g e a re d s h a ft a n d th e
A s s o rte d
p o in t s a re a v a ila b le f o r
s h a ft3 ( F ig 1 3 ); a w e ig h t t h a t s lid e s
s c r e w h a s a b a ll u n iv e r s a lly m o u n te d
m o s t re v e rs e m a lle ts . T h e y a re d e
a lo n g a s h a ft th a t is s p r in g - p r o p e lle d
a t th e t ip .
s ig n e d to e n g a g e th e m a r g in o f th e
( G r e n fe ll, J .W ., p e rs o n a l c o m m u n ic a
c r o w n , e n g a g e th e
tio n )
in t e r p r o x im a l
( F ig
1 4 ); a n d
th e
1 2 ); a
e le c tr o
m a g n e tic re v e rs e m a lle t, p o w e r e d b y
C LAM PS A N D JAW S FO R USE W IT H
m a r g in , o r e n g a g e th e p o n t ic a re a o f
PERCUSSIO N IN S T R U M E N T S .1,2 T h e
f ix e d p a r t ia l d e n tu r e s . R e v e rs e m a l
e le c tr o m a g n e t ic e n e r g y 10 ( F ig
p r i n c ip a l o f d e s ig n o f th e s e d e v ic e s is
le ts c a n p ro d u c e d a n g e ro u s a n g u la r
E le c tr o m a g n e tic re v e rs e m a lle ts a re
to g ra s p th e o u te r s u rfa c e o f a c r o w n
fo rc e s lik e th o s e c re a te d b y th e u s e o f
n o t y e t a v a ila b le b u t t h e y re p r e s e n t
1 5 ).
a n in te r e s tin g c o n c e p t. F L U ID O R H Y D R A U L IC P R E S S U R E D E N T A L C R O W N E L E V A T O R .11 U s e o f t h is e le v a to r r e q u ir e s d r i l l i n g a h o le in th e o c c lu s a l s u rfa c e o f th e c r o w n , in t o w h ic h
a s p e c ia l c o n n e c t o r is
th re a d e d . T h e c o n n e c to r is a tta c h e d to a p u m p , a n d f l u i d p re s s u re f r o m th e p u m p is fo r c e d in t o th e in n e r s id e o f th e c r o w n th a t is b o n d e d to th e to o th . W h e n s u f f ic ie n t f l u i d p re s s u re is c re a te d o n th e in n e r s id e o f th e c r o w n , th e c e m e n t b o n d s e p a ra te s , a n d th e c r o w n
is r e m o v e d . F l u i d
p re s s u re d e n ta l c r o w n re m o v e rs ( F ig 1 6 ) a re n o t c u r r e n t ly a v a ila b le . SELECTED IN S T R U M E N T S FO R PR Y IN G . U s e o f p r y i n g in s tr u m e n t s is m a in ly
a p p l ic a b le
to b in d in g
or
f i r m l y a f fix e d c r o w n s a t th e t im e o f f i t t i n g a n d to t e m p o r a r ily c e m e n te d c ro w n s . A
la r g e s p o o n e le v a to r o r
s m a ll s u r g ic a l e le v a to r c a n b e u s e fu l Fig 10 ■ C & R C row n A dapter for u se w ith percu ssio n instrum ents.
f o r r e m o v in g “ s t u c k ” o r t e m p o r a r ily O liv a : R E M O V IN G C A S T G O L D R E S T O R A T IO N S ■ 843
R E V IE W
A R T IC L E
c e m e n te d c r o w n s w h e n p la c e d in th e i n t e r p r o x im a l m a r g in o r a t th e m a r g in a l r id g e a n d u s e d w i t h a p r y in g
r
fo rc e . H o r n 1 s u g g e s ts th e u s e o f a d u lle d h o e s c a le r (O rb a n ty p e ) — n o . 5 a n d n o . 6 s c a le rs a re e ffe c tiv e i n re m o v in g a c r y lic c r o w n s a n d f ix e d p a r t i a l d e n tu re s . In s tr u m e n ts f o r p r y i n g a re in e ff e c t iv e i n r e m o v in g p e rm a
F ig 12 ■ R everse m a llet w ith w eig h t that slid e s alon g shaft and accessory points.
n e n t ly c e m e n te d c r o w n s a n d , w h e n u s e d a t m a r g in s , c a n i r r e p a r a b ly d a m a g e th e t o o t h o r c r o w n . C R O W N R E M O V IN G FORCEPS. F o r c e p s a re u s e fu l f o r r e m o v in g c r o w n s t h a t a re t e m p o r a r ily c e m e n te d o r b in d in g a t th e t im e o f f it t in g . F o rc e p s
Fig 13 ■ W eighted-hand le reverse m allet— h a n d le slid e s alon g shaft.
a re n o t u s e fu l f o r r e m o v in g c r o w n s t h a t a re p e r m a n e n t ly c e m e n te d a l t h o u g h t h e y c a n b e u s e d to r e m o v e c ro w n s
th a t
w e re
p r e v io u s ly
lo o s e n e d b y o th e r m e a n s . F o r r e m o v a l o f p e r m a n e n t ly
c e m e n te d
c r o w n s , K a r n o f f 8 d e s c r ib e d u s e o f m o d if ie d fo rc e p s f o r r e m o v in g o r Fig 14 ■ Sp rin g-propelled w eig h t typ e cro w n rem over and seater.
t h o d o n t ic b a n d s . A l l th e d e s c rib e d fo rc e p s , e x c e p t th e m o d if ie d fo rc e p s used
f o r r e m o v in g
o r th o d o n tic
b a n d s , e n g a g e th e f a c ia l a n d lin g u a l a x ia l s u rfa c e s o f a c r o w n w i t h s e r r a te d b e a ks o r s h a rp p o in ts . H o w e p lie r s ( F ig 1 7 ), B a a d e p lie r s ( F ig 1 8 ) w i t h a d ju s ta b le s c re w s a n d s h a rp b e a k s ,4 a n d B a c k h a u s c la m p s ( F ig
1 9 ), w h i c h m u s t h a v e s h a r p
b e a k s to b e e ffe c tiv e (F is h e r, D ., p e r Fig 15 ■ E lectrom agnetic reverse m allet.
s o n a l c o m m u n ic a t io n ) , a re u s e d w i t h r o c k in g a n d t w is t in g fo rc e to r e m o v e c r o w n s . M o d if ie d p lie r s f o r r e m o v in g o r t h o d o n t ic b a n d s ( F ig 2 0 ), d e s c r ib e d b y K a r n o ff ,8 u se a s h a rp b e a k th a t e n g a g e s th e a x ia l s u rfa c e o f th e c r o w n a t th e g in g iv a l s u rfa c e a n d th e o th e r e n d o f th e p lie r s is in s e r te d in t o a p r e d r ille d h o le i n th e o c c lu s a l s u r fa c e o f th e c r o w n . B y c lo s in g th e p lie r s , fo rc e is a p p lie d a g a in s t th e o c c lu s a l to o t h s tr u c tu r e as th e s h a rp b e a k p rie s th e c r o w n in a n o c c lu s a l d ir e c t io n . K a r n o ff 8 s u g g e s ts t h a t a c r o w n w i t h a h o le in th e o c c lu s a l s u r fa c e is n o t h i n g t h o d o n t ic b a n d .
m o r e th a n a n o r
COPPER B A N D A N D CEM EN T O N RED CO M PO U N D . E w in g 9 s u g g e s ts u s e o f a c o p p e r b a n d f i l l e d w it h c e m e n t a n d a n a il t h r o u g h th e b a n d (F ig 2 1 ). A f t e r th e c e m e n t h a s h a rd e n e d , a r o c k in g a c t io n o n th e n a il w i l l lo o s e n th e c r o w n a n d p e r m it re m o v a l. Fig 16 ■ F luid p ressure dental crow n elevator.
8 4 4 ■ J A D A , V o l. 9 9 , N o v e m b e r 1 9 7 9
A s im ila r te c h n iq u e in v o lv e s u s e o f r e d c o m p o u n d in a c o p p e r b a n d a n d ,
R E V IE W
A R T IC L E S
Fig 17 ■ H ow e curved and straight p liers— serrated tips.
Fig 2 0 ■ M o d ified p lier s for rem ovin g or th odontic bands described by Karnoff.
Fig 18 ■ B aade pliers— adjustable screw and sharp beaks.4
Fig 21 ■ C opper band— cem en t an d n ail.
re v e rs e m a lle t f o r r e m o v in g c r o w n s a n d c o p in g s . C U T T IN G A S L O T W IT H A B U R A N D in s te a d o f a n a il, a lo o p e d le n g th o f b ra s s w ir e pa sse s th r o u g h th e c o p p e r
d e n tis t d e c id e s t h a t th e c r o w n is n o t
b a n d ( F ig 2 2 ). W h e n th e r e d c o m
t o b e r e p a ir e d a n d r e c e m e n te d o r th a t
p o u n d c o o ls , f o r c e f u l je r k in g o n th e
th e d e v ic e s a n d t e c h n iq u e s p r e v i
b ra s s w ir e o r u s e o f a p e rc u s s io n i n
o u s ly d e s c rib e d a re to o h a z a rd o u s ,
s tr u m e n t r e s u lts i n sa fe r e m o v a l o f
th e s a fe s t m e t h o d o f r e m o v a l is to c u t
th e c r o w n .
a s lo t a n d p r y th e c r o w n lo o s e w i t h
Fig 19 ■ B ack haus cla m p s m u st have sharp b eaks to be effective.
P R Y IN G W IT H IN S T R U M E N T S . I f th e
u s e o f a n in s t r u m e n t . 1‘3,9' 13 A s lo t is A C R Y L IC R E S IN CO PIN G . T h is te c h
c u t w i t h a h ig h - s p e e d c a r b id e b u r f o r
n iq u e w a s s u g g e s te d b y G a rv e r 12 a n d
m e ta l o r w it h
in v o lv e s th e u s e o f a c o p in g o f c o ld -
p o r c e la in . T h e s lo t is c u t in th e c r o w n
c u r in g a c r y lic r e s in th a t p r o v id e s a
ju s t t o th e d e p th o f th e c e m e n t, f r o m
m e c h a n ic a l p u rc h a s e ( F ig 2 3 ) f o r a
th e g in g iv a l m a r g in , u p th e fa c ia l s u r
a d ia m o n d b u r f o r
O liv a : R E M O V IN G C A S T G O L D R E S T O R A T IO N S
■ 845
R E V IE W
A R T IC L E
fa ce , a c ro s s th e o c c lu s a l s u rfa c e , a n d d o w n th e lin g u a l s u rfa c e w i t h i n 1.5 to 1 .0 m m
t io n ) . 9 T h e R i c h w i l c r o w n r e m o v e r is
o f th e lin g u a l g in g iv a l
p la c e d o n th e o c c lu s a l s u rfa c e o f th e
m a r g in . T h e u n c u t m e ta l a t th e l i n
c r o w n a n d th e p a tie n t is a s k e d to c lo s e in t o th e s u b s ta n c e ; t h is c o m
g u a l g in g iv a l m a r g in
k e e p s th e
h a lv e s o f th e c r o w n to g e th e r w h e n
p re s s e s i t b e t w e e n t h e
th e c e m e n t b o n d is b ro k e n . I f th e
t o o t h a n d c r o w n . R e m o v a l o f th e
o p p o s in g
c r o w n is c u t c o m p le te ly in h a lf, th e
c r o w n is a c c o m p lis h e d b y o p e n in g
f i r s t h a l f w i l l lo o s e n w i t h
p r y in g
th e m o u t h w i t h a r a p id a n d f o r c e f u l
fo rc e a n d i t w i l l c o m e o ff. T h is d o e s n o t le a v e a f u lc r u m to p r y a g a in s t to
m o t io n . A f t e r r e m o v a l, th e c r o w n w i l l b e t e m p o r a r ily a tta c h e d to th e
re m o v e th e o th e r h a lf o f th e c r o w n .
r e m o v e r a n d th e o p p o s in g to o th . T h e
A f t e r th e s lo t is c u t, a n a p p r o p r ia te
r e m o v e r a n d a tta c h e d c r o w n a re r e
in s t r u m e n t , s u c h as a la r g e s p o o n
m o v e d f r o m th e o p p o s in g to o th b y
e le v a t o r o r s u r g i c a l e le v a t o r , is
g r a s p in g t h e
p la c e d i n th e s lo t a n d p r y i n g fo rc e is
w i t h a s m a ll p ie c e o f g a u z e . R e m o v e r
a p p lie d
d i s t a l l y u n t i l th e c e m e n t
s u b s ta n c e is e a s ily w a s h e d f r o m th e
b o n d s e p a ra te s . T h e in s t r u m e n t is
s u rfa c e o f th e c r o w n w i t h so a p a n d
c ro w n a n d re m o v e r
th e n re v e rs e d a n d fo rc e is d ir e c te d
w a r m w a te r. A n y r e m a in in g p o r t io n
m e s ia lly ; th e lo o s e n e d h a lf o f th e
o f th e r e m o v e r s u b s ta n c e th a t is a t
c r o w n is u s e d as a f u lc r u m . W h e n th e c e m e n t b o n d o f th e m e s ia l h a lf o f th e
ta c h e d to th e o p p o s in g to o th c a n b e
Fig 22 ■ C opper band— red com pound and brass w ire loop.
c ro w n
s o lv e d w i t h
s e p a r a te s , g e n t l e f o r c e is
ta k e n o f f w i t h a n in s tr u m e n t o r d is w a rm
w a te r . C li n ic a l
a p p lie d i n a n o c c lu s a l d ir e c t io n a n d
ju d g m e n t h a s t o b e u s e d w h e n t r y in g
th e c r o w n is r e m o v e d .
to r e m o v e a c r o w n w i t h t h is te c h
R IC H W IL C R O W N A N D B R ID G E RE
r a r y a d h e s io n o f th e s u b s ta n c e . I f th e
M O VER . R ic h w il c ro w n re m o v e rs
o p p o s in g t o o t h o r its r e s to r a tio n is o f
( F ig 2 4 ), a c o m p le t e ly n e w c o n c e p t,
d o u b t f u l fir m n e s s , it , r a th e r t h a n th e
a re c o m p o s e d o f a s u b s ta n c e o f p l i
d e s ire d c r o w n , m a y b e re m o v e d .
n iq u e b e c a u s e o f th e s tr o n g te m p o
a b le r e s in w i t h
s t r o n g te m p o r a r y
a d h e s iv e p r o p e r tie s . R e m o v e rs are c o n v e n ie n tly
shaped
and
s iz e d .
T h e r e is n o n e e d f o r d r i l l i n g a h o le ,
D is c u s s io n A s c a n e a s ily b e o b s e rv e d f r o m th e
c la m p in g w i t h c la w s o r ja w s , p r y in g ,
in v e n te d
o r u s in g
p e r c u s s io n in s t r u m e n t s .
te c h n iq u e s , r e m o v a l o f c r o w n s is a
d e v ic e s
and
d e s c r ib e d
F o rc e f o r c r o w n r e m o v a l is g e n e ra te d b y th e p a tie n t. T h e s u b s ta n c e a d h e re s
c h a lle n g e th a t te s ts th e in t e llig e n c e ,
to th e s u rfa c e o f te e th a n d to g o ld ,
o f d e n tis ts . B e fo re 1 9 0 7 , r e m o v a l o f
p o r c e la in , a n d a c r y lic r e s in . U s e o f
c r o w n s w a s r e la t iv e ly s im p le . T h e
in g e n u ity , im a g in a tio n , a n d a b ili t y
R ic h w il c r o w n r e m o v e rs se e m s to b e
c o n to u r e d a x ia l b a n d w i t h s w a g e d
th e le a s t t r a u m a t ic a n d d e s tr u c tiv e
o c c lu s a l c r o w n s o f g o ld p la te w a s
m e th o d o f c r o w n re m o v a l y e t d e
e a s ily r e m o v e d w i t h
Fig 23 ■ A cry lic resin coping for m echanical
s c rib e d . I n i t i a l c lin ic a l te sts o f th e
c r o w n s litt e r . S in c e 1 9 0 7 , w h e n T a g
pu rchase.
re m o v e rs
s u c c e s s fu l
g a r t 14 in t r o d u c e d a m e th o d o f c a s tin g
( R a u t h , T . , p e r s o n a l c o m m u n ic a
g o ld , r e m o v a l o f c r o w n s h a s b e c o m e
a re p r o v i n g
Fig 24 ■ R ich w il crow n rem over. Left, rem over (A) placed on occlu sa l o f crow n (B) to be rem oved. Center, re m over (A) com pressed betw een cro w n (B) and natural tooth (C). R ight, rem over (A) attached to crow n (B) and nat ural tooth (C) w hen patient op en s m outh. 8 4 6 ■ J A D A , V o l. 9 9 , N o v e m b e r 1 9 7 9
th e u s e o f a
R E V IE W
p ro g ressiv ely m o re d ifficult as ca st in g te c h n iq u e s w ere perfected. Be c a u se p o rc e la in -fu s e d -to -m e ta l cro w n s h av e delicate p o rce lain sh ell o v er th in m e ta l c o p in g s, th e ir r e m o v al is ev en m ore com plicated. W hen, try in g to rem ove a crow n, th e d e n tist sh o u ld alw ays p roceed w ith c a u tio n . T h e le a s t p o s s ib le a m o u n t of force sh o u ld b e ap p lied . If th e d e n tist ever h as a d o u b t or rese r v atio n ab o u t th e success of th e p ro ced u re, h e sh o u ld stop before an u n n ecessary p ro b lem a n d trau m atic ex p erie n ce are created. R egardless of th e selected d evice or te ch n iq u e , the p a tie n t s h o u ld alw ays be info rm ed of th e p ro ce d u re an d possib le co m p li cations.
Summary M ost te c h n iq u e s a n d devices d e scrib ed for cro w n rem oval, in one w ay or ano th er, d estroy th e in teg rity o f to d a y ’s p r e c is io n c a st c ro w n s. T h ere w ere on ly th ree te c h n iq u e s d e
scrib ed th a t do n o t req u ire d rillin g a h ole, cu ttin g a n o tc h o r slot, c la m p in g w ith claw s or jaw s, p ry in g w ith in stru m e n ts, or g rasp in g w ith fo r cep s a n d p liers. T h ese are th e co p p e r b a n d fille d w ith ce m en t,9 th e co p in g of co ld -c u rin g acry lic re s in ,17 an d th e R ichw il cro w n rem over. T he safest a n d least trau m atic of all cro w n re m o v a l d e v ic e s a n d te c h n iq u e s is to cu t a slo t a n d p ry th e crow n loose. A lth o u g h th e cro w n is d e stro y e d , d am ag e to th e to o th is avoided.
The author thanks W illiam Bishop, University o f California at Los A n geles, S ch ool o f D en tistry, Dental Illustration Department, for th e il lustrations. Dr. O liva is assistant professor, section of fixed prosthodontics, School of Dentistry, U n i versity o f California at Los A n geles, 90024. A d dress requests for reprints to the author. 1. Horn, H.R. Practice con sid eration s for su ccessfu l crow n and bridge therapy. P h ilad el phia, W. B. Saunders Co., 1976. 2. T y lm a n , S.D . T h eory and p r a c tic e o f
A R T IC L E
crow n and bridge p rosth od on tics, ed 5. St. L ouis, C. V. M osby Co., 1965. 3. Roberts, D.H. Fixed bridge prosthesis. In stitute of Dental Surgery, Eastman D ental H os pital, Bristol, John W right & Son s, Ltd. 1973, p 225. 4. Kornfeld, M. M outh rehabilitation. C lini cal and laboratory procedures, ed 2. St. L ouis, C. V. M osby, 1974 p 584. 5. Sarti, J. Inlay extractor. U S Patent no. 2 ,6 4 0 ,2 6 6 J u n e 2 ,1 9 5 3 . 6. Border, S.L. R em oving tooth restorations. U S Patent no. 2,464,289, March 1949. 7. Lynch, H.F., and others. D evice for rem ov in g restoration s from teeth . U S P aten t no. 2,591,451, A pril 1952. 8. K am off, E.M. R em oving cem en ted crow ns and bridges w ith out destroying them . NYJ D en tal 4 5 (5 ):1 5 8 -1 5 9 ,1975. 9. E w in g , J.E. F ix e d p a r tia l p r o s th e s is . P h iladelph ia, Lea & Febiger, 1959, p 188. 10. Brodie, S.S., and others. A pparatus for the rem oval of cem en ted dental structures. US Patent no. 3,377,704, A pril 16, 1968. 11. Ballard, L.M. Dental crow n elevator. US Patent no. 3,653,127, A pril 4 ,1 9 7 2 . 12. Garver, D.S. A safe crow n-rem oval tech nique. ] Prosthet Dent 39(l):56-58, 1978. 13. W einberg, L.A. A tlas o f crow n and bridge prosthodontics. St. L ouis, C. V. M osby, 1965, p 226. 14. T aggart, W .H . A n e w an d a ccu rate m ethod of m aking gold inlays. Dent C osm os 49:1117-1121, 1907.
O li v a : R E M O V I N G C A S T G O L D R E S T O R A T IO N S ■ 8 4 7
